ArriveCan is also voluntary. A great idea. But voluntary.
Would I use it? Sure.
Would I willingly hand my phone over to a *Canadian* customs officer on a cursory request at the booth so they can see if I have a certain app installed and chastise me over it? Nope.
When they send me to secondary then I’d gladly let them have a look under the guidelines set forth.
CBSA policy Footnote 1 states that examinations of personal devices should not be conducted as a matter of routine; such searches may be conducted only if there are grounds or indications that “evidence of contraventions may be found on the digital device or media.
A border guard at the booth wanting to see if you have a voluntary app installed on your phone does not qualify.
I’ll gladly have a polite discussion at secondary with the officers there on the topic.
I used to cross the border twice a day every day. I don’t have anything in the closet, but I also know my rights, and have no problem exercising them when I feel someone is stepping beyond theirs.
"Yes sir, no sir", works wonders. Save's having to wait for the escort to secondary and then the time spent there.